Every episode of the famed drama series Mad Men features the mostly male cast taking slow, epic drags from a cigarette. And if the show had been set in 1950s Tokyo, instead of Manhattan, their smoking habits would have seemed even more dramatic.

During the "age of Don Draper," four out of five men were smoking in Japan, but despite its ubiquity, Japanese men from the post-WWII generation had surprisingly low rates of lung cancer.

To investigate this paradox, Japanese public health officials capitalized on a national database that monitored smoking habits every year for more than six decades.

"Many of the data collected during these surveys - including everything collected between 1949 and 1957 - have never been published or analyzed in the medical literature," wrote Ikuko Funatogawa, first author and a cancer biostatician at Teikyo University.

While smoking was pervasive among Japanese men during the 1950s, they found most of these smokers started at a much older age relative to men in the U.S. This trend is likely due to a ban issued in 1900 that prevented minors under the age of 20 from buying cigarettes.

Findings show that smoking among male children and teenagers is extremely rare in Japan but has been relatively common (>10%) within the white male population of the United States for several decades.

Researchers warn, however, that younger generations in Japan have started picking up the habit in their teens, which could lead to more cancer in the future.

Only one out of five Japanese women were smokers in the 1950s, a rate which has held steady for 60 years. In contrast, the number of female smokers has doubled over the past 30 years in the U.S. As a result, smoking-related deaths among American women are far more common.